There was a very small point in nothingness. No, not a vacuum, but nothingness. No matter, no antimatter, just nothing. This point was very hot, and very dense. It was smaller than an atom. It quickly expanded, to many, many times its size, becoming the size of a golf ball. This golf ball sized chunk of matter expanded until it exploded with a bang, kickstarting the universe.
The Universe's Age
According to space.com, scientists can determine the age of the universe using two different methods: by studying the oldest objects within the universe and measuring how fast it is expanding. They came up with 13.8 billion years old. That's a lot of candles!
The formula scientists used to calculate the age of the universe.
The Universe's Size
We can only see where there is light. If there is no light, we humans cannot see. So technically can only see 13.8 billion light years away. This is true if the universe is not expanding because the universe is 13.8 billion years old. Thirteen point eight billion years of light travelling. But, the universe is always expanding so humans can see 23 billion light years away from either direction. The actually size of the universe is unknown, although scientists do have a ballpark estimate of 93 billion light years in diameter.
The universe is expanding. But why? The universe is expanding because of the momentum left behind from the Big Bang and dark energy. Apparently the momentum left from the Big Bang was so strong, the universe is accelerating at 67 kilometers per second. That speed is incredibly fast. Moving at that speed, you could travel around the entire world at the equator in just 10 minutes! Now the universe acceleration rate is also getting faster. Too fast, and a rip could pull the entire universe apart.
The universe could split into many pieces.
The universe is enchanting. It has so many secrets that scientists may never figure out. It also has secrets that are right in front of their faces, but they just don't know it. These answers above were just four secrets of the universe that were revealed to us. There are plenty of other questions to ask: What shape is the universe? What's beyond the universe? Are there other universes? The universe is just a vague space of emptiness from our first view. But deep down, it has so much to answer, so much to explore. Our perspective of the universe is very limited. We are just a speck in this vast space, bigger than we can imagine. The universe is a wonder that scientists will never find all of its secrets.